현상

아래 코드 실행 시 다음과 같은 에러가 발생하며 MouseArea 적용이 되지 않음

main.qml:13:9: Unable to assign QQuickWindowQmlImpl to QQuickItem

• main.py

  import os
  from pathlib import Path
  import sys
  
  from PySide2.QtGui import QGuiApplication
  from PySide2.QtQml import QQmlApplicationEngine
  
  
  if __name__ == "__main__":
      app = QGuiApplication(sys.argv)
      engine = QQmlApplicationEngine()
      engine.load(os.fspath(Path(__file__).resolve().parent / "main.qml"))
      if not engine.rootObjects():
          sys.exit(-1)
      sys.exit(app.exec_())
  

• main.qml

  import QtQuick 2.15
  import QtQuick.Window 2.15
  
  Window {
      id: root
  
      width: 640
      height: 480
      title: "Hello, world"
      visible: true
  
      MouseArea {
          anchors.fill: root
  
          onClicked: {
              root.title = "Clicked"
          }
      }
  }
  

원인

anchor 속성은 성능상의 이유로 같은 depth의 컴포넌트나 바로 상위 컴포넌트만 설정할 수 있다.

https://doc.qt.io/qt-5/qtquick-positioning-anchors.html#restrictions

For performance reasons, you can only anchor an item to its siblings and direct parent. For example, the following anchor is invalid and would produce a warning:

해결 방안

• main.qml

  import QtQuick 2.15
  import QtQuick.Window 2.15
  
  Window {
      id: root
  
      width: 640
      height: 480
      title: "Hello, world"
      visible: true
  
      MouseArea {
          anchors.fill: parent      // root -> parent로 수정
  
          onClicked: {
              root.title = "Clicked"
          }
      }
  }
  

참고

• https://doc.qt.io/qt-5/qtquick-positioning-anchors.html#restrictions